Trailer light Plug Wiring The fifth wire is connected, at the vehicle end, to the backup lights. It is used to acculate the solinoid which would block the flow of brake fluid which is necessary to allow disk brakes equiped trailers to back up. If you don't have brakes it goes nowhere.
Thom
"The amount S&P 500 corporations owe to their employee's retirement benefits plans for which they have set aside no funds: $458,000,000,000" |